Effect of Reaction Conditions on Pore Configuration and Mechanical Property for Porous Hydroxyapatite Prepared by Polymer Sponge Method

2007 ◽  
Vol 336-338 ◽  
pp. 1567-1570 ◽  
Author(s):  
Sang Ho Min ◽  
Hyeong Ho Jin ◽  
B.S. Jun ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
...  

Porous HAp scaffolds have been prepared by using the slurry including HAp and magnesia based on the replication of polymer sponge substrate. The influence of HAp and MgO content in slurry on the pore morphology and size, and density, porosity, and mechanical strength of porous HAp scaffolds was investigated. The obtained scaffolds with average pore sizes ranging 150 to 300 μm had open, relatively uniform, and interconnected porous structure regardless of HAp and MgO content. As the MgO content increased, the pore network frame of scaffolds became to be relatively stronger, even though the pore size was not much changed. The compressive strength of the scaffolds increased rapidly with the increase of MgO content at a fixed HAp content because of increasing the pore wall thickness and density of the scaffolds. As a result, the porosity, density, and compressive strength of the porous HAp scaffolds scaffolds prepared by the sponge method were significantly affected by the addition of MgO.

2006 ◽  
Vol 510-511 ◽  
pp. 754-757 ◽  
Author(s):  
Sang Ho Min ◽  
Hyeong Ho Jin ◽  
Hoy Yul Park ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
...  

Porous hydroxyapatite (HAp) scaffolds were successfully prepared by using the HAp slurry based on the replication of polymer sponge substrate. The effect of HAp content in slurry on the pore morphology and size, and density, porosity, and mechanical strength of porous scaffolds was investigated. The scaffolds with average pore sizes ranging from 200 to 400 µm had an open, relatively uniform, and interconnected porous structure. As the HAp content increased, the porosity of scaffold decreased while the density increased. These phenomena were attributed to the fact that the pores became interconnected with more dense and thicker pore walls with increasing HAp content in slurry. The results suggest that the density, porosity, and compressive strength of the porous HAp scaffold were significantly affected by the content of the HAp powder in the slurry.


2010 ◽  
Vol 105-106 ◽  
pp. 616-619 ◽  
Author(s):  
Li Li Wang ◽  
Xiu Feng Wang ◽  
Hong Tao Jiang ◽  
Cheng Long Yu

Hydroxyapatite (HA) doped with 3%yttria-stabilized 20wt% zirconia (ZrO2) ceramic were developed in order to produce a porous composite biomaterial by integrating the gel-casting technique with polymer sponge method with improved mechanical strength and controllable porous structure. The pore morphology, size, and distribution of the scaffolds were characterized using an electron microscope. The scaffolds prepared have an open, uniform and interconnected porous structure with a pore size of 300~500m. The porosity of the open pores in the scaffold can be controlled by changing HA-ZrO2 composite concentration and it is between 87%~35%. A compressive strength of 12MPa for HA-ZrO2 porous scaffolds with HA-ZrO2 concentration of 55wt% was achieved, which is comparable to that of cortical bone.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Li-Jie Liu ◽  
Jin-Hong Li ◽  
Xiang Wang ◽  
Ting-Ting Qian ◽  
Xiao-Hui Li

Abstract High-porosity magnesia phosphate paste (HPMPP) was prepared via the pre-foaming method. In the pre-foaming method, sintering treatment was not required. The bulk density and maximum compressive strength of the HPMPP prepared according to the ratio of water to solids (W/So) of 0.32 reached 464.00 ± 5.00 Kg/m3 and 0.30 ± 0.05 MPa, respectively. The compressive strength increased with the increases in the addition amounts of sodium silicate and polypropylene fibers. The bulk density of HPMPP increased with the increase in the addition of sodium silicate and decreased with the increase in the addition of polypropylene fibers. Besides, the porosity of the magnesia phosphate paste increased from 79.85% to 81.27% and from 80.31% to 83.75% after the addition of sodium silicate and polypropylene fibers respectively. The highest porosity (83.75%) of the prepared HPMPP was realized under the addition proportion (sodium silicate: polypropylene fibers: solids = 0.06:0.0025:1). The average pore size of the prepared HPMPP is about 180 μm and the pore distribution range is relatively narrow. The hydration product (struvite) is combined with MgO particle one by one and then coated on the surface of bubbles. With the decrease of the water content, after breaking bubbles, the porous structure can be achieved.


2020 ◽  
Vol 1000 ◽  
pp. 132-138
Author(s):  
Ahmad Fadli ◽  
Feblil Huda ◽  
Komalasari ◽  
Ilham Habib ◽  
Arosyidin

Macroporous hydroxyapatite have been used in biomedical application especially for bone graft. The objective of this research was to study the effect of yolk addition, rate of sintering temperature rise, and rate of stirring on the physical, chemical and mechanical properties of porous hydroxyapatite prepared using protein foaming-starch consolidation method. The slurry was made by mixing the hydroxyapatite and starch powder with Darvan 821A and yolk in a beaker glass. The slurry was stirred mechanically at rate of 150 rpm for 3 hours and it poured in cylindrical mold. Subsequently the slurry was heated in air oven at 180°C for 1 hour. The dried green bodies were burn out at 600°C ended by sintering at 1250°C. The porous hydroxyapatite with average pore size in the range of 13.7-17.9 μm, porosity of 59.3-63.6 % and compressive strength of 5.17-8.2 MPa was obtained. The calculation result of response surface methodology shows that p-value < 0.05 and lack of fit > 0.05. The most effecting factor significantly was hydroxyapatite addition that followed by mixing rate and temperature rising rate of sintering. Optimum condition hydroxyapatite addition of 22 gr, mixing rate of 150 rpm and temperature rising rate of sintering of 2.8°C/minutes with the optimum value of response for pore size by 17.665 μm, porosity by 63.475% and compressive strength 5.17 MPa.


2014 ◽  
Vol 910 ◽  
pp. 23-26
Author(s):  
Lie Feng Liang ◽  
Jun Jie Chen ◽  
Yong He ◽  
Dai Yang Li

A new technique to prepare macroporous hydroxyapatite (HA) scaffolds was introduced. Porous HA ceramics were prepared by sol-gel method from chitin dissolved in dimethylacetylamide (DMAc) / lithium chloride (LiCl) solvent, three dimensional stacking with HA gel fibers and pore agent. The blocks dried were heated to optimum sintering temperature of 1280°C. The porous HA ceramics reinforced by homogeneous fibers, with interconnected pores and high porosity and pore-diameter were obtained, whilst improving mechanical strength. Sintered ceramics were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis confirmed that the crystal structure remained HA. SEM showed the samples presented a highly interconnected porous reticulate structure with average pore size ranging from 340μm to 450μm. The porosity was varied from 61% to 83%. The maximum compressive strength of HA ceramic was 3.4MPa.The mechanical strength of samples was improved with addition of homogeneous fibers.


2013 ◽  
Vol 302 ◽  
pp. 61-65
Author(s):  
Yoo Taek Kim ◽  
Jun Young Park

The purpose of this study is to enhance the mechanical strength of specimens containing fly ash from fluidized bed type boiler, which the recycling rate will be eventually increased. Specimens containing fly ash in a certain portion were made and aged for 3, 14, and 21 days. The carbonation process under the super critical condition was performed to enhance the mechanical property of specimens by filling the voids and cracks existing inside cement specimen with CaCO3 reactants. The additional aging effect after the supercritical carbonation process on mechanical strength of specimens was also investigated by comparing the compressive strength with and without 7 day extra aging. Carbonation under the supercritical condition and additional 7 day aging was very effective for enhancement of mechanical strength and compressive strength increased by 44%, which reached up to 88MPa.


Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.


2021 ◽  
Vol 13 (14) ◽  
pp. 7593
Author(s):  
Farooq Khan Niazi ◽  
Malik Adeel Umer ◽  
Ashfaq Ahmed ◽  
Muhammad Arslan Hafeez ◽  
Zafar Khan ◽  
...  

Ultrafiltration membranes offer a progressive and efficient means to filter out various process fluids. The prime factor influencing ultrafiltration to a great extent is the porosity of the membranes employed. Regarding membrane development, alumina membranes are extensively studied due to their uniform porosity and mechanical strength. The present research work is specifically aimed towards the investigation of nanoporous alumina membranes, as a function of sintering parameters, on ultrafiltration performance. Alumina membranes are fabricated by sintering at various temperatures ranging from 1200–1300 °C for different holding times between 5–15 h. The morphological analysis, conducted using Scanning electron microscopy (SEM), revealed a homogeneous distribution of pores throughout the surface and cross-section of the membranes developed. It was observed that an increase in the sintering temperature and time resulted in a gradual decrease in the average pore size. A sample with an optimal pore size of 73.65 nm achieved after sintering at 1250 °C for 15 h, was used for the evaluation of ultrafiltration performance. However, the best mechanical strength and highest stress-bearing ability were exhibited by the sample sintered at 1300 °C for 5 h, whereas the sample sintered at 1250 °C for 5 h displayed the highest strain in terms of compression. The selected alumina membrane sample demonstrated excellent performance in the ultrafiltration of sugarcane juice, compared to the other process liquids.


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